On Apr 24, 2008, at 10:48 AM, Jeff Squyres (jsquyres) wrote:
You probably want to use all the intel compilers, not just ifort. CC=icc CXX=icpc FC=ifort F77=ifort
I have long used gcc and ifort on 64-bit Linux (since SUSE did 64-bit Linux on AMD Opterons), I don't see a good reason why OS X should be be/remain a problem.
There are very major reasons to use gcc and ifort. It works and buying a bunch of ifort C licenses is an unnecessary expense, unless there is some type of speed advantage to compiling OpenMPI with the Intel compilers instead of gcc.
Given that we have very little C code that requires a highly optimized compiler for the latest Intel Xeon we will continue to use gcc when building OpenMPI. However, given that ifort generates code that is 7.7 times faster under Linux than that generated by latest g95 and gfortran in my tests on a 5300-series Xeon (first dual quad 3.0 GHz Mac Pro) we will also continue using ifort for the foreseeable future.
Strangely g95 is 2.7 times faster under OS X (with virus-checking) than under g95 under Linux on a 5100-series Xeon (first quad 2.66 GHz Mac Pro). This is something I will test again with Intel's OS X Fortran compiler against their Linux compiler to see if there is a difference there.
Michael
